Biomedical adhesive compositions

Abstract

Novel non-elastomeric biomedical adhesive compositions for calcified tissues, are described. The compositions are characterized by a network structure which is obtained by the reaction of a polyisocyanate having at least two isocyanate groups with at least one polyol which possesses surface wetting properties with the participation of compounds selected from calcium and phosphorus, optional in the presence of a catalyst. The polyisocyanate is selected from aliphatic, alicyclic and aromatic compounds and preferred amounts are in the range of 20% to 80% by weight of the total amount of reactants. The polyol is selected from polyalkylene ether glycols and polyester glycols containing between 25 to 75 carbon atoms and preferred amounts are in the range of 10% to 80% by weight of the total amount of reactants. The adhesive compositions were found to produce a fast bonding of the calcified tissues, with a joint strength of above 0.5 N/sq.mm.

We claim: 
     
       1. A composition consisting of a network to be obtained by the reaction of a polyisocyanate having at least two isocyanate groups, in an amount which ranges between 20% to 80% by weight of the total amount of reactants with at least one polyol which possesses surface wetting properties in an amount of between 10% to 80% by weight of the total amount of reagents, with the participation of compounds containing calcium and phosphorus, said polyisocyanate being selected from the group consisting of aliphatic, alicyclic and aromatic polyisocyanates, said polyol being selected from the group consisting of polyalkylene ether and glycols containing between 25 and 55 carbon atoms, said compounds containing calcium and phosphorus being present in an amount sufficient to permit said adhesive composition to produce bonding of calcified tissues with a joint strength of at least 0.2 N/sq. mm., said composition being a non-elastomeric biomedical adhesive composition which is degradable by physiological enzymes and which is biocompatible. 
     
     
       2. The non-elastomeric biomedical adhesive composition according to claim 1, wherein said network is obtained in the presence of a catalyst. 
     
     
       3. The non-elastomeric biomedical adhesive composition according to claim 1, wherein said polyisocyanate is: tolylene 2,4-diisocyanate, tolylene 2,6-diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 1,12-diisocyanatododecane, 1,6-diisocyanatohexane, 4,4',4"-triphenylmethane triisocyanate, mixtures thereof or combinations with another polyisocyanate. 
     
     
       4. The non-elastomeric biomedical adhesive composition according to claim 1, wherein said polyol is polyester glycol containing between 25 and 55 carbon atoms. 
     
     
       5. The non-elastomeric biomedical adhesive composition according to claim 1, wherein said polyol is: sorbitan monolaurate, sorbitan monostearate, polyoxyethylene (20) sorbitan monopalmitate, polyoxyethylene (20) sorbitan monooleate, sorbitan mono-9-octo-decenoate, lauryl gallate or any mixture thereof. 
     
     
       6. The non-elastomeric biomedical adhesive composition according to claim 1, wherein an additional polyol may be incorporated being selected from the group consisting of: glycerol, ethylene glycol, polyethylene glycol, polypropylene glycol, poly-tetrahydrofuran, polycaprolactone diol, glycerol monostearate and polycaprolactone triol. 
     
     
       7. The non-elastomeric biomedical adhesive composition according to claim 1, wherein said compounds of calcium and phosphorus, are selected from tricalcium phosphate, hydroxyapatite, calcium salt of phosphorglyceric acid, glucose-6-calcium salt of phosphoric acid and glucose-1-calcium salt of phosphoric acid. 
     
     
       8. The non-elastomeric biomedical adhesive composition according to claim 2, wherein the optional catalyst to be used is selected from: sodium trichlorophenate, sodium tetrachlorophenate, sodium pentachlorophenate, ferric 2-ethylhexanoate, ferric acetylacetonate, dibutyltin-di-2-ethylhexanoate,stannous- 2-ethylhexanoate and cobalt 2-ethylhexanoate. 
     
     
       9. The non-elastomeric biomedical adhesive composition according to claim 1, wherein an inert filler is incorpoted. 
     
     
       10. The non-elastomeric biomedical adhesive composition according to claim 9, wherein said inert filler is selected from carbon black, metal oxides, stabilizers, ceramic powders, acrylic and methacrylic resin powders, and plasticizers.